WO2008130106A1

WO2008130106A1 - Local wire and wireless communication system, and method of inter-networking calls and performing handoff

Info

Publication number: WO2008130106A1
Application number: PCT/KR2008/001786
Authority: WO
Inventors: Ki-Hong Bang; Ho-In Lee
Original assignee: Axstone Co., Ltd.
Priority date: 2007-04-24
Filing date: 2008-03-31
Publication date: 2008-10-30

Abstract

The present invention relates to a local wire/wireless communication system, a method of inter-networking calls using the system, and a method of performing a handoff. According to an embodiment of the invention, a local wire/wireless communication system includes: a wireless network connecting unit that provides a wireless connection interface to a public satellite network or a public wireless network; an information storage unit that stores subscriber information of the local wireless terminal, the subscriber information including information of a person who subscribes to the public satellite network or the public wireless network; a local wireless base station that provides a wireless connection interface to the local wireless terminal, and connects the local wireless terminal to the public satellite network or the public wireless network through the wireless network connecting unit; and a control unit that controls the information storage unit, the wireless network connecting unit, and the local wireless base station, and provides the same service as that in the public satellite network or the public wireless network to the local wireless terminal. The wireless network connecting unit uses the same wireless standard as that in the public satellite network or the public wireless network, and uses the subscriber information in the public satellite network or the public wireless network, which is stored in the information storage unit, to perform connection to the public satellite network or the public wireless network. According to the present invention, a subscriber of a local wire/wireless communication service can access an external public satellite or a commercial wireless network in a local service area, using the same subscriber information as that in a commercial wireless network. Further, even when the subscriber of the local wire/wireless communication service moves out of the local service area while talking with a subscriber of the public satellite network or the commercial wireless network over the telephone in the local service area, the handoff is performed to continuously provide a call service to the subscriber without call interruption.

Description

LOCAL WIRE AND WIRELESS COMMUNICATION SYSTEM,

AND METHOD OF INTER-NETWORKING CALLS AND

PERFORMING HANDOFF

Technical Field

[1] The present invention relates to a local wire/wireless communication system. More specifically, the present invention relates to a local wire/wireless communication system for connecting a wire/wireless terminal in a local service area to an external public satellite network, a public wireless network, or a public wire network, to a method of inter-networking calls using the system, and to a method of performing a handoff. Background Art

[2] In recent years, with the development of a private exchange technique as well as a mobile communication technique, various wire and wireless office solutions (WWOS) have been used to provide various specialized additional services in a limited service area, such as the inside of a building, and of a satellite communication network and a mobile communication network such as WiMAX (worldwide interoperability for microwave access), GSM (global system for mobile communications), CDMA (code division multiple access), or W-CDMA (wideband-CDMA).

[3] The local wire/wireless communication system that provides a communication service in a limited area, sich as a building, a campus, or a factory, can provide not only a basic service of a wireless network, such as the existing public satellite network or mobile communication, to local wire/wireless terminals in the limited area, but can also provide an independent connection service to an external network to local wire/ wireless terminals in an independent system, using a wireless connection standard that is the same as or different from an external satellite communication standard or an external mobile communication standard. R>r example, similar to CDMA mobile communication outside the building, the CDMA mobile communication can be performed inside the building, or, inside the building, local wire/wireless terminals using different wireless communication systems, such as Wi-MAX, Wi-H, and general phones, can receive additional services for private network users as well as the services of an external network.

[4] However, in the local wire/wireless communication system according to the related art, when a subscriber of the local wire/wireless communication service moves from the outside of a local service area to the inside or from the inside of the local service area to the outside thereof, a dedicated line connected to the public satellite network or the commercial wireless network is needed to transmit or receive calls with a subscriber number used outside the local service area and a subscriber number used in the public satellite network or the commercial wireless network. In addition, a dedicated protocol should be used to register the position of the subscriber and to process calls. In this case, a load applied to the public satellite network or the commercial wireless network increases, and costs for the dedicated line, increase. In addition, the costs of equipment for the local wire/wireless communication increase, which causes difficulties in spreading the local communication service.

[5] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Disclosure of Invention Technical Problem

[6] The present invention has been made in an effort to provide a local wire/wireless communication system that enables a subscriber of a local wire/wireless communication service to axess an external public satellite network or a commercial wireless network in a local service area, using the same subscriber information as that in a commercial wireless network, a method of inter-networking calls using the system, and a method of performing a handoff.

[7] The present invention has also been made in an effort to provide a local wire/wireless communication system that performs a handoff to continuously provide a local wire/ wireless communication service without call interruption, even when a subscriber of the local wire/wireless communication service moves out of a local service area while talking with a subscriber of a public satellite network or a commercial wireless network over a telephone, a method of inter-networking calls using the system, and a method of performing the handoff. Technical Solution

[8] In order to achieve the objects, aooording to an embodiment of the present invention, there is provided a local wire/wireless communication system for providing a local wire/wireless communication service to a local wireless terminal positioned in a local service area. The system includes: a wireless network connecting unit that provides a wireless connection interface to a public satellite network or a public wireless network; an information storage unit that stores subscriber information of the local wireless terminal, the subscriber information including information of a person who subscribes to the public satellite network or the public wireless network; a local wireless base station that provides a wireless connection interface to the local wireless terminal, and connects the local wireless terminal to the public satellite network or the public wireless network through the wireless network connecting unit; and a control unit that controls the information storage unit, the wireless network connecting unit, and the local wireless base station, and provides the same service as that in the public satellite network or the public wireless network to the local wireless terminal. The wireless network connecting unit uses the same wireless standard as that in the public satellite network or the public wireless network, and uses the subscriber information in the public satellite network or the public wireless network, which is stored in the information storage unit, to perform connection to the public satellite network or the public wireless network.

[9] According to another embodiment of the present invention, a method of allowing a local wire/wireless communication system to connect an originating call from a local wireless terminal or a local wire terminal positioned in a local service area to a public satellite network, a public wireless network, or a public wire network is provided. The method includes: receiving the originating signal from the local wireless terminal or the local wire terminal to establish a traffic channel to the local wireless terminal or the local wire terminal; requesting the public satellite network, the public wireless network, or the public wire network to establish call connection, using information of a user of the local wireless terminal or the local wire terminal who subscribes to the public satellite network, the public wireless network, or the public wire network; when a call response is received from a called terminal corresponding to the originating call, which is connected to the public satellite network, the public wireless network, or the public wire network, establishing a traffic channel to the public satellite network, the public wireless network, or the public wire network; and performing voice transmission/reception between the local wireless terminal or the local wire terminal and the called terminal through the traffic channel that is established between the local wireless terminal or the local wire terminal and the public satellite network, the public wireless network, or the public wire network.

[10] Aooording to still another embodiment of the present invention, there is provided a method of allowing a local wire/wireless communication system to connect a call signal received from a public satellite network, a public wireless network, or a public wire network to a local wireless terminal or a local wire terminal positioned in a local service area. The method includes: receiving a call from a called terminal corresponding to a call that is originated from a calling terminal connected to the public satellite network, the public wireless network, or the public wire network; determining whether the called terminal is of a subscriber of the local wire/wireless communication system; when it is determined that the called terminal is of the subscriber of the local wire/wireless communication system, transmitting the received call to the local wireless terminal or the local wire terminal to establish a traffic channel to the local wireless terminal or the local wire terminal; and when a response is received from the local wireless terminal or the local wire terminal, performing voice transmission/ reception between the local wireless terminal or the local wire terminal and the calling terminal through the traffic channel that is established between the local wireless terminal or the local wire terminal and the public satellite network, the public wireless network, or the public wire network.

[11] According to yet another embodiment of the present invention, there is provided a method of performing a handoff for a local wireless terminal that is positioned in a local service area of a local wire/wireless communication system when the local wireless terminal moves out of the local service area during wireless communication with an external wire/wireless terminal connected to a public satellite network or a public wireless network. The method includes: receiving a wireless state report message from the local wireless terminal; determining whether to start the handoff on the basis of the wireless state report message; when it is determined to start the handoff on the basis of the wireless state report message, transmitting the wireless state report message to the public satellite network or the public wireless network to receive a handoff direction message; and transmitting the handoff direction message to the local wireless terminal. Advantageous Effects

[ 12] According to the present invention, a subscriber of a local wire/wireless communication service can access an external public satellite network or a commercial wireless network in a local service area, using the same subscriber information as that in a commercial wireless network. Therefore, it is not necessary to provide a dedicated line connected to the public satellite network or the commercial wireless network, and a dedicated protocol is not needed to register the position of a subscriber and process calls.

[13] Further, even when a subscriber of a local wire/wireless communication service moves out of a local service area while talking with a subscriber of a public satellite network or a commercial wireless network over a telephone, a handoff process is performed to continuously provide the local wire/wireless communication service without call interruption. Brief Description of the Drawings

[14] FIG. 1 is a diagram schematically illustrating the concept of a local wire/wireless communication system according to an exemplary embodiment of the present invention.

[15] FIG. 2 is a detailed block diagram illustrating the local wire/wireless communication system shown in FIG. 1.

[16] FIG. 3 is a flowchart illustrating a method of connecting an originating call from a wireless terminal in a local service area to an external wireless network in the local wire/wireless communication system according to the exemplary embodiment of the present invention.

[17] FIG. 4 is a flowchart illustrating a method of connecting an originating call from the external wireless network to the wireless terminal in the local service area in the local wire/wireless communication system according to the exemplary embodiment of the present invention.

[18] FIG. 5 is a flowchart illustrating a handoff method when the local wireless terminal moves out of the local service area during wireless communication with the external wireless terminal in the local wire/wireless communication system according to the exemplary embodiment of the present invention. Best Mode for Carrying Out the Invention

[19] In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

[20] It will be understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The terms "-er" "-or" and/or "module," when used in this specification, mean units each of which processes at least one function or operation and may be implemented by hardware, software, or a combination of hardware and software.

[21] In the specification, a terminal (MS) may indicate a mobile station (MS), a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), user equipment (UE), or an access terminal (AT), or it may include some or all of the functions of the mobile terminal, the subscriber station, the portable subscriber station, and the user equipment.

[22] In the specification, a base station (BS) may indicate an access point (AP), a radio access station (RAS), a node B, a base transceiver station (BTS), or an MMR (mobile multihop relay)-BS, or it may include some or all of the functions of the access point, the radio access station, the node B, the base transceiver station, and the MMR-BS.

[23] The present invention is characterized in that, in connection to a public satellite network or a commercial wireless network, a local wire/wireless communication system provides a service to local wire/wireless communication subscribers in a local service area, using a wireless network connecting unit in the local wire/wireless communication system, which provides the same wireless standard as that used in a public satellite network or a commercial wireless network, by the same wireless communication method as that in the public satellite network or the commercial wireless network, or a wire/wireless communication technique, which is independent from an external wireless network technique on the basis of the same subscriber information as that a local wire/wireless communication subscriber in a local service area, without using a connection method using a dedicated line and a dedicated protocol.

[24] Hereinafter, a local wire/wireless communication system according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[25] FIG. 1 is a diagram schematically illustrating the concept of the local wire/wireless communication system according to the exemplary embodiment of the present invention, and FIG. 2 is a detailed block diagram illustrating the local wire/wireless communication system shown in FIG. 1.

[26] As shown in FIGS. 1 and 2, a local wire/wireless communication system 100 according to the exemplary embodiment of the present invention provides a local wire/ wireless communication service to local wire telephones or SIP terminals 11 and wireless terminals 12 that are located in a local service area 10 corresponding to a limited area, such as a building, a campus, or a factory, in the areas in which a communication service is available through a commercial wireless network or a public satellite network 200 corresponding to a mobile communication network, such as WiMAX, GSM, CDMA, or W-CDMA.

[27] In addition, the local wire/wireless communication system 100 can interwork with commercial wireless network or a public satellite network 200, and can be connected to an external public network through a PSTN (public switched telephone network) 400 and an IP network 600. The local wire/wireless communication system 100 can be connected to an external wire phone 500 through the PSTN 400, and can also be connected to an external SIP terminal 700 through the IP network 600.

[28] The local wire/wireless communication system 100 includes a local wireless base station 110, a wireless network connecting unit 120, a wire network connecting unit 130, an information storage unit 140, and a control unit 150.

[29] The local wireless base station 110 provides a wireless communication service to the wireless terminal 12 of a subscriber who wants to use a local wire/wireless communication service using the local wire/wireless communication system 100 (hereinafter referred to as "a local wire/wireless communication subscriber"), and uses the wireless communication standard that is the same as that used in an external public satellite network or the commercial wireless network 200 to perform wireless communication with the wireless terminal 12.

[30] The wireless terminal 12 performs local wire/wireless communication through a local wireless base station 110 in the local service area 10, but can perform external public satellite communication or commercial wireless communication through the public satellite network or the commercial wireless network 200 outside of the local service area 10. FIG. 2 shows an example in which a CDMA terminal 12 is used as the wireless terminal 12 when mobile communication is performed using a CDMA system among various kinds of mobile communication systems.

[31] Referring to FIG. 2, the local wireless base station 110 includes a wireless transceiver 111 that performs wireless communication with the CDMA terminal 12, and a base station CDMA modem 112 that controls CDMA communication between the wireless transceiver 111 and the CDMA terminal 12.

[32] Meanwhile, the wireless network connecting unit 120 connects wire/wireless terminals in the local service area 10, for example a local wire phone 11-1, an SIP terminal 11-2, and a wireless terminal 12, to the external public satellite network or the commercial wireless network 200. In order to perform the connection, the wireless network connecting unit 120 is connected to the wire network connecting unit 130 and the local wireless base station 110. Specifically, as shown in FIG. 2, a LAN switch 160 connects the local wireless base station 110, the wireless network connecting unit 120, and the wire network connecting unit 130 to form a path for transmitting data.

[33] Referring to FIG. 2, the wireless network connecting unit 120 includes a plurality of

CDMA modules 121-1, 121-2, ..., 121-n for connection to the commercial wireless network 200, and a serial to LAN converter 122 for data transmission between the plurality of CDMA modules 121-1, 121-2, ..., 121-n and the LAN switch 160.

[34] The plurality of CDMA modules 121-1, 121-2, ..., 121-n in the wireless network connecting unit 120 connect the CDMA terminal 12, which is in the local service area 10 that is wirelessly connected through local wireless base station 110, and the external commercial wireless network 200. The plurality of CDMA modules 121-1, 121-2, ..., 121-n use subscriber information of the CDMA terminal 12 that is wirelessly connected through the local wireless base station 110 to perform the same call processing on the external commercial wireless network 200 using the same number information and the same wireless standard. Therefore, the existing dedicated line that is connected to the external public satellite network or the commercial wireless network in order to process separate signals is not needed, and a dedicated protocol is not needed.

[35] Further, the plurality of CDMA modules 121 - 1 , 121 -2, ..., 121 -n can use a mobile communication service through the external commercial wireless network 200 on the basis of the subscriber information of the CDMA terminal 12, like the CDMA terminal 12. Therefore, in addition to the local wire phone/SIP terminal 11 in the local service area 10, other accessible wire/wireless terminals can transmit or receive a call with the same terminal number as that of the CDMA terminal 12, and receive the same additional services, such as a caller-ID service, as those when the CDMA terminal 12 is used outside. This is because the plurality of CDMA modules 121-1, 121-2, ..., 121-n can use the subscriber information of the CDMA terminal 12 to wirelessly access the external commercial wireless network, as such CDMA network 200, and then be connected to the local wireless base station 110 and the wire network connecting unit 130 through the serial to LAN converter 122 and the LAN switch 160 to transmit or receive data.

[36] In this embodiment, the wireless network connecting unit 120 includes the plurality of CDMA modules 121-1, 121-2, ..., 121-n, but the technical range of the present invention is not limited thereto. When the external commercial wireless network 200 is a public satellite network or when it corresponds to another mobile communication network, the wireless network connecting unit 120 may include a plurality of modules that can be wirelessly connected using a wireless communication standard used in the external public satellite network or other mobile communication networks.

[37] Meanwhile, the wire network connecting unit 130 connects wire/wireless terminals in the local service area 10, for example the local wire telephone/SIP terminal 11-1 and 11-2 and the wireless terminal 12, and external wire networks, that is, the PSTN 400 and the IP network 600. Ibr example, the wire network connecting unit 130 is connected to the PSTN 400 through a private branch exchange that is connected to a dedicated line through a media gateway, which is well-known. Therefore, a detailed description thereof will be omitted.

[38] Meanwhile, the information storage unit 140 stores various information items required to provide the local wire/wireless communication service, particularly information of the local wire/wireless communication subscribers. When the wireless network connecting unit 120 receives an originating call from the wireless terminal 12 in the local service area 10 through the local wireless base station 110, the information storage unit 140 provides information of the subscriber. Therefore, the wireless network connecting unit 120 receives the subscriber information transmitted from the information storage unit 140, and can provide an originating call service using an ID number and information of the subscriber. Referring to FIG. 2, the information storage unit 140 stores information of local wire/wireless communication subscribers, particularly information of subscribers using the mobile communication service provided through the commercial wireless network 200. When receiving an originating call from the CDMA terminal 12 in the local service area 10, the CDMA modules 121-1, 121-2, ..., 121-n receive subscriber information of the CDMA terminal 12 from the information storage unit 140, and can receive a mobile communication service using the ID number and information of the CDMA terminal 12.

[39] The control unit 150 is connected to the local wireless base station 110, the wireless network connecting unit 120, the wire network connecting unit 130, the information storage unit 140, and the LAN switch 160, and controls the local wire/wireless communication system 100 to be normally operated.

[40] The control unit 150 includes a RAM 151, a flash memory 152, and a central processing unit 153. The control unit 150 may further include various constituent elements other than the above to provide various functions. However, in this em- bodiment, the control unit 150 includes only the above components, as an example.

[41] The RAM 151 is a cache memory, and temporarily stores various programs executed by the control unit 150 and various data processed by the control unit 150.

[42] The flash memory 152 stores various programs executed by the control unit 150.

[43] The central processing unit 153 uses the flash memory 152 and the RAM 151 to control the local wireless base station 110, the wireless network connecting unit 120, the wire network connecting unit 130, the information storage unit 140, and the LAN switch 160.

[44] Meanwhile, the LAN switch 160 controls data transmission/reception paths among the local wireless base station 110, the wireless network connecting unit 120, and the wire network connecting unit 130 under the control of the control unit 150.

[45] Next, a wireless network access method in the local wire/wireless communication system according to the exemplary embodiment of the present invention will be described with reference to FIGS. 3 and 4.

[46] FIG. 3 is a flowchart illustrating a method of connecting an originating call from the wireless terminal in the local service area to an external wireless network in the local wire/wireless communication system according to the exemplary embodiment of the present invention.

[47] FIG. 3 shows the operation of the CDMA terminal 12 (hereinafter referred to as a

"local wireless terminal") in the local service area 10 transmitting a call to an external CDMA terminal 300 (hereinafter referred to as an "external wireless terminal") through the external commercial wireless network 200 (hereinafter referred to as an "external wireless network").

[48] Hrst, the wireless terminal of a person who subscribes to a wireless communication service using the external wireless network 200 and also subscribes to the local wire/ wireless communication service according to the exemplary embodiment of the present invention enters the local service area 10, and serves as the local wireless terminal 12. When the local wireless terminal 12 transmits a call to the external wireless terminal 300, call origination starts (SlOO), and a call origination request is wirelessly transmitted from the local wireless terminal 12 to the local wireless base station 110 (SlOl). The local wireless base station 110 receives the call origination request and transmits the request to the control unit 150 through the LAN switch 160.

[49] Therefore, under the control of the control unit 150, the local wireless base station

110 sets a traffic channel to the local wireless terminal 12 (S 102), and transmits a ringback tone start request to the local wireless terminal 12 such that the local wireless terminal 12 transmits a ringback tone to the subscriber (S 103).

[50] Then, under the control of the control unit 150, the local wireless base station 110 performs number translation using a called number that receives the originating call (S 104). Then, the local wireless base station 110 receives the subscriber information of the local wireless terminal 12 transmitted from the information storage unit 140 under the control of the control unit 150, and transmits the translated called number and the call origination request to the CDMA module 120 (hereinafter referred to as a "wireless terminal module") (S 105).

[51] Therefore, the wireless terminal module 120 requests the external wireless network

200 to transmit a call, using the subscriber information of the local wireless terminal 12 transmitted from the local wireless base station 110 (S106). Then, a traffic channel is established between the wireless terminal module 120 and the external wireless network 200 according to a response from the external wireless network 200 (S 107).

[52] Then, the external wireless network 200 transmits the ringback tone start request in response to the call origination request from the wireless terminal module 120 (S 108), and pages an external wireless terminal 300 corresponding to the called number that will receive the originating call (S 109).

[53] The traffic channel is set between the external wireless network 200 and the external wireless terminal (300) according to the response of the external wireless terminal 300 (Sl 10). When the external wireless terminal 300, which is a called terminal, transmits a response signal (Sill), the response from the called party is transmitted to the wireless terminal module 120 through the external wireless network 200 having the traffic channel established therein (S 112 and S 113). In this case, the external wireless network 200 establishes the traffic channel to the external wireless terminal 300, which is the called terminal, and transmits the response from the called party, regarding the wireless terminal module 120 as the local wireless terminal 12. Therefore, voice transmission/reception is available between the wireless terminal module 120 and the external wireless terminal 300, and the originating call is completely processed. However, in the exemplary embodiment of the present invention, since the local wireless terminal 12 is the actual caller, the wireless terminal module 120 should transmit the response of the called party transmitted from the external wireless terminal 300, which is the called terminal, to the local wireless terminal 12 through the local wireless base station 110 having the traffic channel established therein, in order to establish the actual traffic channel between the local wireless terminal 12 in the local service area 10 and the external wireless terminal 300. [54] In this way, the local wireless base station 110 and the wireless terminal module 120 provide the traffic channel between the local wireless terminal 12 in the local service area 10 and the external wireless terminal 300 connected to the external wireless network 200, and thus voice transmission/reception can be performed between the local wireless terminal 12 and the external wireless terminal 300 (S 116). In this case, voice transmission/reception is wirelessly performed between the local wireless terminal 12 and the local wireless base station 110, and voice transmission/reception using an IP is performed between the local wireless base station 110 and the wireless terminal module 120. In addition, voice transmission/reception is wirelessly performed among the wireless terminal module 120, the external wireless network 200, and the external wireless terminal 300.

[55] In this embodiment, the external wireless network 200 provides a wireless communication service to the external wireless terminal 300, but the invention is not limited thereto. It will be understood by those skilled in the art that the embodiment of the invention can be applied to an external wire network that provides a wire communication service to a wire terminal with reference to the drawings and the above description. In this case, it will be apparent to those skilled in the art that voice transmission/reception is performed between the external wire network and the external wire terminal by wire.

[56] Meanwhile, in this embodiment, the local wireless terminal 12 in the local service area 10 transmits an originating call to the external wireless terminal 300 connected to the external wireless network 200, but the technical scope of the present invention is not limited thereto. For example, the operation of the local wire terminal 11 in the local service area 10 transmitting an originating call to the external wireless terminal 300 connected to the external wireless network 200 may be performed most similarly to that described with reference to FIG. 3. The local wire terminal 11 may be the local wire phone 11-1 or the local SEP terminal 11-2.

[57] The difference between this case and the operation described with reference to FIG.

3 is as follows.

[58] The local wire terminal 11 in the local service area 10 starts call origination, and the wire network connecting unit 130 receives the originating call from the local wire terminal 11 and transmits a call origination request to the wireless terminal module 120. Therefore, a traffic channel is established among the local wire terminal 11, the wire network connecting unit 130, and the wireless terminal module 120.

[59] When receiving the call origination request from the local wire terminal 11, the wire network oonnecting unit 130 establishes a traffic channel to the local wire terminal 11, transmits a ringback tone start request to the local wire terminal 11, and perform number translation using a called number that receives the originating call under the control of the control unit 150.

[60] The wire network oonnecting unit 130 receives subscriber information of the local wire terminal 11 transmitted from the information storage unit 140 under the control of the control unit 150, and transmits the translated called number and the call origination request to the wireless terminal module 120.

[61] The wireless terminal module 120 requests the external wireless network 200 to transmit an originating call, using the subscriber information of the local wire terminal 11 transmitted from the wire network connecting unit 130, to establish a traffic channel to the external wireless terminal 200.

[62] In this way, the wire network connecting unit 130 and the wireless terminal module

120 provide the traffic channel between the local wire terminal 11 in the local service area 10 and the external wireless terminal 300 connected to the external wireless network 200, and thus voice transmission/reception can be performed between the local wire terminal 11 and the external wireless terminal 300. In this case, voice transmission/reception is performed between the local wire terminal 11 and the wire network connecting unit 130 by wire.

[63] It will be easily understood from the above description that the local wire terminal 11 in the local service area 10 can transmit a call signal to the external wire terminal connected to the external wire network, which provides a wire communication service to the wire terminal, to transmit or receive voice signals.

[64] Next, a method of transmitting a call signal from the external wireless terminal 300 to the local wireless terminal 12 in the local service area 10 will be described.

[65] FIG. 4 is a flowchart illustrating a method of connecting an originating call from the external wireless network to the wireless terminal in the local service area in the local wire/wireless communication system according to the exemplary embodiment of the present invention.

[66] FIG. 4 shows the operation of the local wireless terminal 12 in the local service area

10 receiving a call signal transmitted from the external wireless terminal 300.

[67] Erst, when the external wireless terminal 300 connected to the external wireless network 200 transmits a call signal to the local wireless terminal 12 in the local service area 10, call origination starts (S200), and a call origination request is wirelessly transmitted from the external wireless terminal 300 to the external wireless network 200 (S201). Then, the external wireless network 200 establishes a traffic channel to the external wireless terminal 300 (S202), and pages a called terminal corresponding to a called number that receives the originating call (S203).

[68] Meanwhile, when the external wireless network 200 pages a called terminal, the wireless terminal module 120 in the local wire/wireless communication system 100 checks whether a subscriber corresponding to the called number subscribes to the local wire/wireless communication service (S204). The wireless terminal module 120 checks whether the subscriber corresponding to the called number subscribes to the local wire/wireless communication service on the basis of the subscriber information stored in the information storage unit 140 under the control of the control unit 150.

[69] When it is checked in step S204 that the called number is not of the local wire/ wireless communication subscriber, the called number is discarded.

[70] When it is checked in step S204 that the called number is of the local wire/wireless communication subscriber, under the control of the control unit 150, the wireless terminal module 120 transmits the called number to the local wireless base station 110 to page a terminal corresponding to the called number (S205).

[71] Then, the local wireless base station 110 transmits a page message to check whether there is a local wire/wireless communication subscriber corresponding to the called number in the local service area 10, and performs a called terminal paging process to check whether the local wireless terminal 12 responds to the message (S206).

[72] If it is found that there is no subscriber corresponding to the called number in the local service area 10, it is determined in step S205 that there is no response to the called terminal paging process, and the called number is discarded.

[73] However, if it is found that the subscriber corresponding to the called number is present in the local service area 10 and a response to the called number paging process is received from the local wireless terminal 12 (S207), the local wireless base station 110 transmits the response to the called number paging process to the terminal module 120 under the control of the control unit 150 (S208). When receiving the response to the called number paging process from the local wireless terminal 12, the local wireless base station 110 establishes a traffic channel to the local wireless terminal 12 (S209).

[74] Since a terminal that receives a call signal from the external wireless terminal 300 exists in the local service area 10, the wireless terminal module 120 transmits a page response message including the subscriber information of the local wireless terminal 12 stored in the information storage unit 140 to the external wireless network 200, thereby responding to the called number paging under the control of the control unit 150 (S210). Then, a traffic channel is established between the wireless terminal module and the external wireless network 200 having received the response to the called number paging (S211).

[75] As described above, when the local wireless terminal 12 in the local service area 10 responds to an originating call from the external wireless terminal 300, the external wireless network 200 transmits a ringback tone start request to the external wireless terminal 300 (S212).

[76] Meanwhile, after the traffic channel is established between the local wireless terminal 12 and the local wireless base station 110 (S209), when the local wireless terminal 12, which is a called terminal, transmits a response (S213), the response from the called party is transmitted to the wireless terminal module 120 through the local wireless base station 110 having the traffic channel established therein (S214 and S215).

[77] Therefore, since the local wireless terminal 12, which is the actual called terminal, transmits the response, instead of the local wireless terminal 12, the wireless terminal module 120 uses the subscriber information of the local wireless terminal 12 to transmit a called-party response to the external wireless network 200 (S216). The response is transmitted to the external wireless terminal 300 (S217), and voice transmission/reception is available between the wireless terminal module 120 and the external wireless terminal 300. In addition, since the traffic channel is established between the wireless terminal module 120 and the local wireless terminal 12, the local wireless terminal 12 can receive the originating call from the external wireless terminal 300, and voice transmission/reception can be performed between the external wireless terminal 300 and the local wireless terminal 12 (S218).

[78] In this case, voice transmission/reception is wirelessly performed between the local wireless terminal 12 and the local wireless base station 110, and voice transmission/ reception using an IP is performed between the local wireless base station 110 and the wireless terminal module 120. In addition, voice transmission/reception is wirelessly performed among the wireless terminal module 120, the external wireless network 200, and the external wireless terminal 300.

[79] In the above embodiment described with reference to FIG. 4, the external wireless network 200 provides a wireless communication service to the external wireless terminal 300, but the invention is not limited thereto. It will be understood by those skilled in the art that the embodiment of the invention can be applied to an external wire network that provides a wire communication service to a wire terminal with reference to the drawings and the above description. In this case, it will be apparent to those skilled in the art that voice transmission/reception can be performed between the external wire network and the external wire terminal by wire.

[80] In addition, a procedure in which the local wire terminal 11 in the local service area

10 serves as a called terminal that receives an originating call from the external wireless terminal 300 through the external wireless network 200 or an originating call from the external wire terminal through the external wire network will be easily understood from the above description. However, as an example, the subscriber of the local wireless terminal 12 can use the control unit 150 to control the wireless terminal module 120 to connect the originating call received from the external wireless network 200 to the local wireless base station 110 or the wire network connecting unit 130, which is well-known. Thus, a detailed description thereof will be omitted.

[81] Next, a handoff method that is capable of providing a call service without call interruption when the local wireless terminal 12 moves out of the local service area 10 while connecting a voice call to the external wireless terminal 300 will be described below.

[82] FIG. 5 is a flowchart illustrating a handoff method when the local wireless terminal moves out of the local service area while connecting a call to the external wireless terminal in the local wire/wireless communication system according to the exemplary embodiment of the present invention.

[83] Referring to FIG. 5, first, the local wireless terminal 12 in the local service area 10 establishes a traffic channel through the local wireless base station 110, the wireless terminal module 120, and the external wireless network 200 according to the method described with reference to FIGS. 3 and 4, and connects a voice call to the external wireless terminal 300 (S300 and S301).

[84] In this state, when the local wireless terminal 12 moves out of the local service area

10, the call between the local wireless terminal 12 and the external wireless terminal 300 is disconnected. In order to prevent the call disconnection, in this exemplary embodiment of the present invention, before the call between the local wireless terminal 12 and the external wireless terminal 300 is disconnected, a handoff is performed to connect the local wireless terminal 12 to the external wireless network 200.

[85] In order to perform the handoff, the local wireless base station 110 checks a wireless state report message indicating the wireless state of the local wireless terminal 12, which is transmitted from the local wireless terminal 12 (S302), and determines whether to perform the handoff between the local wireless terminal 12 and the external wireless network 200 when it is found that the wireless state of the local wireless terminal 12 is not able to provide a call service higher than a predetermined level (S303). for example, as the wireless state report message indicating the wireless state of the local wireless terminal 12, the following may be used: a pilot strength measurement message (PSMM) indicating the pilot strength of a neighboring base station including the local wireless base station 110, which is measured in the local wireless terminal 12; or a power measurement report message (PMRM) indicating the intensity of power.

[86] If it is determined that the wireless state report message transmitted from the local wireless terminal 12 indicates that the wireless state of the local wireless terminal 12 is able to receive a service higher than a predetermined level from the local wireless base station 110, it is determined that the local wireless terminal 12 is still positioned in the local service area 10. Therefore, the handoff is not performed, and the wireless state report message is discarded.

[87] However, if it is determined that the wireless state report message transmitted from the local wireless terminal 12 indicates that the wireless state of the local wireless terminal 12 is not able to receive a call service higher than a predetermined level from the local wireless base station 110, the local wireless base station 110 determines that the local wireless terminal 12 has moved out of the local service area 10, and determines to start a handoff process.

[88] When determining to start the handoff process for the local wireless terminal 12, the local wireless base station 110 transmits a handoff direction message to the wireless terminal module 120 (S304).

[89] The wireless terminal module 120 receiving the handoff direction message increases the reception strength of a PN offset included in the current active set and PN offsets that are more likely to be included in the active set, and transmits the wireless state report messages (PSMM/PMRM) to the external wireless network 200 (S305). Under the control of the control unit 150, the wireless terminal module 120 uses the subscriber information of the local wireless terminal 12 stored in the information storage unit 140 to transmit the wireless state report message to the external wireless network 200. In addition, the reason why the wireless terminal module 120 increases the reception strength of the PN offset included in the active set and PN offsets that are more likely to be included in the active set is as follows. The reception strength of the PN offset included in the active set and PN offsets that are more likely to be included in the active set, which is included in the wireless state report message received from the local wireless terminal 12, is actually measured by the local wireless terminal 12, and is low since the local wireless terminal 12 is positioned in the local service area 10. The external wireless network 200 may not perform the handoff process. Therefore, the wireless terminal module 120 increases the reception strength, puts the reception strength into the wireless state report message, and transmits the message to the external wireless network 200. Therefore, the external wireless network 200 can perform the handoff process. Thus, the wireless terminal module 120 increases the reception strength of the PN offset included in the active set and PN offsets that are more likely to be included in the active set to a sufficiently large value for the external wireless network 200 to perform the handoff, and the reception strength depends on, for example, the kind and type of external wireless network 200.

[90] The external wireless network 200 receives the wireless state report message transmitted from the wireless terminal module 120, and transmits, to the wireless terminal module 120, a handoff direction message (HDM) to request the wireless terminal module 120, actually, the local wireless terminal 12, to start a handoff process (S306).

[91] When receiving the handoff direction message to start the handoff process from the external wireless network 200, the wireless terminal module 120 transmits the handoff direction message to the local wireless base station 110 as a response to step S304 (S307), and the local wireless base station 110 transmits, to the local wireless terminal 12, a handoff direction message to instruct the local wireless terminal 12 to actually start the handoff process (S308).

[92] Meanwhile, the wireless terminal module 120 and the local wireless base station 110 having received the handoff direction message and the response in steps S306 and

5307 stop wireless transmission to the external wireless network 200 and the local wireless terminal 12, and disconnect a call without the communication of a message (S309 and S310). That is, the wireless terminal module 120 disconnects the call between the external wireless network 200 and the local wireless base station 110, and the local wireless base station 110 disconnects the call between the wireless terminal module 120 and the local wireless terminal 12.

[93] The local wireless terminal 12 having received the handoff direction message in step

5308 performs a handoff process out of the local service area 10, on the basis of information included in the handoff direction message (S311), and is connected to the external wireless network 200 to transmit a handoff completion report to the external wireless network 200 (S312).

[94] Therefore, even when the local wireless terminal 12 is out of the local service area

10, the local wireless terminal 12 performs a handoff to the external wireless network 200 to keep the voice call connection to the external wireless terminal 300 (S313).

[95] At that time, voice transmission/reception is wirelessly performed both between the external wireless network 200 and the local wireless terminal 12 performing the handoff process and between the external wireless network 200 and the external wireless terminal 300.

[96] Similarly, it will be easily understood from the above-mentioned description that, when the local wireless terminal 12 in the local service area 10 moves out of the local service area 10, the local wireless terminal 12 performs a handoff to the external wireless network to keep call connection to the external wire terminalnetwork.

[97] In the above-described embodiment, in order to perform voice call connection, a call is established between the local wire/wireless terminal in the local service area 10 and the external public satellite network, the public wireless network, or the public wire network, but the technical scope of the present invention is not limited thereto. When a short message is transmitted/received between the local wire/wireless terminal and the external public satellite network, the public wireless network, or the public wire network, or a data call is established therebetween to perform data communication, the wireless terminal module 120 in the local wire/wireless communication system 100 may use subscriber information of the local wireless terminal 12 to establish a channel to the external public satellite network, the external public wireless network 200, or the external public wire network, thereby transmitting/receiving a short message or performing data communication.

[98] While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

[1] A local wire/wireless communication system for providing a local wire/wireless communication service to a local wireless terminal positioned in a local service area, the system comprising: a wireless network connecting unit that provides a wireless connection interface to a public satellite network or a public wireless network; an information storage unit that stores subscriber information of the local wireless terminal, the subscriber information including information of a person who subscribes to the public satellite network or the public wireless network; a local wireless base station that provides a wireless connection interface to the local wireless terminal, and connects the local wireless terminal to the public satellite network or the public wireless network through the wireless network connecting unit; and a control unit that controls the information storage unit, the wireless network connecting unit, and the local wireless base station, and provides the same service as that in the public satellite network or the public wireless network to the local wireless terminal, wherein the wireless network connecting unit uses the same wireless standard as that in the public satellite network or the public wireless network, and uses the subscriber information in the public satellite network or the public wireless network, which is stored in the information storage unit, to perform connection to the public satellite network or the public wireless network.

[2] The local wire/wireless communication system of claim 1, further comprising: a wire network connecting unit that is controlled by the control unit, provides a connection interface to a PSTN (public switched telephone network) or an IP network, and provides the local wire/wireless communication service to the local wire terminal in the local service area.

[3] The local wire/wireless communication system of claim 1, further comprising a LAN switch that is controlled by the control unit, and provides data transmission paths among the local wireless base station, the wireless network connecting unit, and the wire/wireless connecting units, wherein the wireless network connecting unit includes: at least one wireless terminal module that is accessible to the public satellite network or the public wireless network, using the same wireless standard as that in the public satellite network or the public wireless network; and a converter that converts data transmitted between the LAN switch and the at least one wireless terminal module.

[4] The local wire/wireless communication system of claim 3, wherein the local wireless base station includes: a wireless transceiver that wirelessly transmits/receives data to/from the local wireless terminal; and a base station modem that transmits data between the wireless transceiver and the LAN switch.

[5] The local wire/wireless communication system of claim 2, wherein the wire network connecting unit uses the subscriber information in the public satellite network or the public wireless network, which is stored in the information storage unit, to connect the local wire terminal to the public satellite network or the public wireless network.

[6] The local wire/wireless communication system of claim 3, wherein the local wireless base station and the wireless network connecting unit connect the local wireless terminal to the public satellite network or the public wireless network to perform a voice call, short message transmission/reception, or data communication therebetween.

[7] A method of allowing a local wire/wireless communication system to connect an originating call from a local wireless terminal or a local wire terminal positioned in a local service area to a public satellite network, a public wireless network, or a public wire network, the method comprising: receiving the originating signal from the local wireless terminal or the local wire terminal to establish a traffic channel to the local wireless terminal or the local wire terminal; requesting the public satellite network, the public wireless network, or the public wire network to establish call connection, using information of a user of the local wireless terminal or the local wire terminal, who subscribes to the public satellite network, the public wireless network, or the public wire network; when a call response is received from a called terminal corresponding to the originating call, which is connected to the public satellite network, the public wireless network, or the public wire network, establishing a traffic channel to the public satellite network, the public wireless network, or the public wire network; and performing voice transmission/reception between the local wireless terminal or the local wire terminal and the called terminal through the traffic channel that is established between the local wireless terminal or the local wire terminal and the public satellite network, the public wireless network, or the public wire network.

[8] The method of claim 7, further comprising: between the establishing of the traffic channel and the requesting of the call connection, transmitting a ringback tone start request to the local wireless terminal or the local wire terminal; and translating a called number included in the originating call, wherein, in the requesting of the call connection, the translated called number is included in the request for the public satellite network or the public wireless network to establish the call connection.

[9] The method of claim 7, wherein the same wireless standard as that used in the public satellite network or the public wireless network is used to establish the traffic channel to the local wireless terminal.

[10] A method of allowing a local wire/wireless communication system to connect an originating call received from a public satellite network, a public wireless network, or a public wire network to a local wireless terminal or a local wire terminal positioned in a local service area, the method comprising: receiving a call from a called terminal corresponding to a call that is originated from a calling terminal connected to the public satellite network, the public wireless network, or the public wire network; determining whether the called terminal is of a subscriber of the local wire/ wireless communication system; when it is determined that the called terminal is of the subscriber of the local wire/wireless communication system, transmitting the received call to the local wireless terminal or the local wire terminal to establish a traffic channel to the local wireless terminal or the local wire terminal; and when a response is received from the local wireless terminal or the local wire terminal, performing voice transmission/reception between the local wireless terminal or the local wire terminal and the calling terminal through the traffic channel that is established between the local wireless terminal or the local wire terminal and the public satellite network, the public wireless network, or the public wire network.

[11] The method of claim 10, wherein the transmitting of the call includes: transmitting the received call to the local wireless terminal or the local wire terminal; receiving a response to the received call from the local wireless terminal or the local wire terminal; transmitting the response to the received call to the public satellite network, the public wireless network, or the public wire network; and establishing both a traffic channel to the local wireless terminal or the local wire terminal and a traffic channel to the public satellite network, the public wireless network, or the public wire network.

[ 12] The method of claim 9, wherein the performing of the voice transmission/reception includes: receiving a response to the received call from the local wireless terminal or the local wire terminal; transmitting the response to the received call to the calling terminal through the public satellite network, the public wireless network, or the public wire network; and performing the voice transmission/reception between the local wireless terminal or the local wire terminal and the calling terminal through the traffic channel established between the local wireless terminal or the local wire terminal and the public satellite network, the public wireless network, or the public wire network.

[13] The method of claim 12, wherein the same wireless standard as that used in the public satellite network or the public wireless network is used to establish the traffic channel to the local wireless terminal.

[14] A method of performing a handoff for a local wireless terminal that is positioned in a local service area of a local wire/wireless communication system when the local wireless terminal moves out of the local service area during wireless communication with an external wire/wireless terminal connected to a public satellite network or a public wireless network, the method comprising: receiving a wireless state report message from the local wireless terminal; determining whether to start the handoff on the basis of the wireless state report message; when it is determined to start the handoff on the basis of the wireless state report message, transmitting the wireless state report message to the public satellite network or the public wireless network to receive a handoff direction message; and transmitting the handoff direction message to the local wireless terminal.

[15] The method of claim 14, wherein, in the determination of the start of the handoff, when it is determined that a service level for the local wireless terminal is equal to or lower than a predetermined level on the basis of the wireless state report message, it is determined to start the handoff.

[16] The method of claim 14, wherein the transmitting of the wireless state report message includes: increasing the reception strength of a PN offset in an active set included in the received wireless state report message and the reception strength of PN offsets to be included in the active set to a sufficient level to receive the handoff direction message from the public satellite network or the public wireless network; and transmitting the wireless state report message to the public satellite network or the public wireless network.

[17] The method of claim 14, wherein the wireless state report message is a pilot strength measurement message (PSMM) indicating the pilot strength of a neighboring base station, which is measured in the local wireless terminal, or a power measurement report message (PMRM) indicating the intensity of power.

[18] The message of claim 17, further comprising, after the transmitting of the handoff direction message, stopping wireless transmission to the local wireless terminal and the public satellite network or the public wireless network, and disestablishing the traffic channel to the local wireless terminal and the traffic channel to the public satellite network or the public wireless network.

[19] The method of claim 17, wherein the same wireless standard as that used in the public satellite network or the public wireless network is used to perform wireless transmission/reception processes including the reception of the wireless state report message from the local wireless terminal and the transmission of the handoff direction message.